It's likely that almost everything that sets hard can be considered food safe, once fully dry/cured. But if you need to be able to show that the filler or any finish you've used is certified as food-safe your standard may have to be very different than if it's just for personal use.
What's the application: cutting board, serving board, tabletop or counter, fruit bowl, other?
This is the most relevant thing I suspect, most dry foods would be fine if in short term contact with a finish certified as Child Safe, I.E. tested to EN71 Part 3 regulations.
"Food Safe" is a far more stringent certification because it is a clearance to certify that it is safe for inclusion in or as foodstuffs. ( I believe it involves immersion/contact with several solvents for extended periods to determine presence of restricted chemical products.)